EP3919842A1 - Structure for storing snow and method for mounting same - Google Patents

Abstract

The invention relates to a snow storage structure (1) comprising: - at least one perforated surface (3) intended to be placed on a ground (100) to maintain the structure in a stable manner on the ground, said openwork surface being suitable to be covered with a pile of snow, - at least one low-emissivity tarpaulin (2) connected to the perforated surface, and intended to cover the pile of snow; and- at least one system (4) for mechanically tensioning the tarpaulin when the latter covers the pile of snow in order to maintain said tarpaulin in contact with the pile of snow. The invention also relates to a method of mounting such a snow storage structure (1).

Description

Field of the invention

The invention relates to the field of snow storage, or “snow farming” in English, from one season to the following season, or even over a few months at the start of the season, with a view to reusing this snow. This snow conservation technique is used by some winter sports resorts because it allows sufficient snow to be available at the start of the following season or at the start of the season.

Prior state of the art

In general, a pile of snow is produced, usually artificially, towards the end of winter in suitable places, typically at the foot of the slopes, and is then covered with an insulating layer comprising mainly sawdust and / or shavings. Of wood. It is thus possible to keep up to 80% of snow from one season to the next. However, this poses the problem that the snow is soiled by the elements of this insulating layer. In addition, this requires many handling when it is desired to remove only a fraction of this heap.

Low emissivity cloths were used to store snow as blankets placed on a pile of snow. However, the snow pile has proven to be mechanically unstable over time and the thermal efficiency is much lower than with sawdust and / or wood chips.

Low emissivity fabrics have also been tested at higher altitudes, for example to protect glaciers. However, this technique is not suitable for conventional ski areas, in which the snow guns are located relatively far from the glacier areas. In addition, the wind resistance of these fabrics is such that a consolidated stowage must be carried out, which requires significant handling both during stowage and over time.

There is therefore no satisfactory solution at the present time making it possible to overcome the problems of the prior art for storing snow from one season to the next. One There remains a need to store snow which will be easily reusable, under conditions which allow most of it to be preserved, while minimizing the need for handling and monitoring the pile of snow thus stored.

On the other hand, it is also important to preserve the snow production at the start of the season. The device is therefore mobile and intended for occasional, strategic use at the start of the season.

The invention consists in alleviating the problems of the state of the art, by proposing a structure for storing snow, as well as a device for mounting said structure.

Disclosure of the invention

• au moins une surface ajourée destinée à être placée sur un terrain pour maintenir la structure de manière stable sur le terrain, ladite surface ajourée étant apte à être recouverte d'un tas de neige,
• au moins une bâche à basse émissivité reliée à la surface ajourée, et destinée à couvrir le tas de neige; et
• au moins un système de mise sous tension mécanique de la bâche lorsque celle-ci recouvre le tas de neige pour maintenir ladite bâche au contact du tas de neige.

According to a first aspect, the invention relates to a snow storage structure comprising:

• at least one perforated surface intended to be placed on a ground in order to maintain the structure in a stable manner on the ground, said openwork surface being suitable for being covered with a pile of snow,
• at least one low-emissivity sheet connected to the perforated surface, and intended to cover the pile of snow; and
• at least one system for mechanically tensioning the tarpaulin when the latter covers the pile of snow to keep said tarpaulin in contact with the pile of snow.

Advantageously, such a structure is mobile. Another advantage of this structure is that it can be used on an ad hoc basis, which can be strategic at the start of the season.

Such a structure advantageously allows good anchoring of the structure and better conservation of snow. In fact, the very nature of the perforated surface allows the snow in the layer of snow on which the perforated surface is placed to enter the openings (or orifices) of the perforated surface and promotes its anchoring to the ground. The openings in the perforated surface also allow the snow deposited above to pass through the perforated surface, by pressure from the piled up mass. A recovery of the gel also allows better adhesion of the snow pile on the perforated surface and on the snow present under the perforated surface. The perforated surface therefore mainly has a function of reinforcing the structure. In addition, the fact of connecting the perforated surface to the tarpaulin makes it possible to participate in maintaining the perforated surface on the ground. Finally, the perforated surface allows the evacuation of melt water possible that could appear during storage.

In addition, the mechanical tensioning of the tarpaulin facilitates anchoring of the tarpaulin in contact with the snow, which advantageously makes it possible to avoid the presence of places free of snow under the surface of the tarpaulin. Such locations would promote wind resistance and would be liable to lead to the formation of water pockets under the cover, which would cause a "magnifying glass" effect, which would lead to the gradual melting of the stored snow. This advantageously makes it possible to improve the performance of snow retention.

Finally, such a structure requires simple handling during its assembly, according to the assembly method of the invention, then limited monitoring because its wind resistance is weak due to its solid anchoring to the ground.

According to the invention, a perforated surface is a surface (or layer) comprising openings. It is most often a single material. This perforated surface mainly has a function of reinforcing the structure, allowing a certain mechanical strength of the structure.

Preferably, the perforated surface is an openwork fabric. The fabric is made from yarns, and may be, as is known to the person skilled in the art, a woven fabric, a nonwoven, a grid or a knit. The term grid is understood to mean a superposition of two sets of parallel threads (or plies), linked for example by gluing at their crossing points.

Even more preferably the fabric is a woven or a grid. This makes it possible to ensure the reinforcement function in a more optimized way.

The perforated surface can be a mesh, that is to say an intersection of generally metallic wires, most often coated with plastic, a PES (poly (ether sulfone) / PVC or glass / PVC type grid According to the invention, the wires of the mesh are generally uniformly covered with polymeric material such as poly (vinyl chloride) (acronym: PVC), polypropylene or typically high density polyethylene (acronym: HDPE). The perforated surface may be a mesh that is that is to say a net type fishing net, the threads of which are knotted.

According to one embodiment, the fabric can be initially full and then perforated by any means known to the person skilled in the art.

The openings of the perforated surface may or may not be identical to each other. They have a greater length dimension of a few millimeters to a few centimeters, preferably 20 to 50 mm. Below 20 mm, the snow deposited above may not pass sufficiently through said surface. Above 50mm anchorage will generally not be sufficient.

According to the invention, a tarpaulin is a large sheet of solid, flexible, water-resistant or impermeable material, typically of textile such as a fabric canvas, for example of polyester coated with polyurethane or PVC, or of plastic material. for example polyethylene. Preferably the tarpaulin is a canvas comprising a PVC coating.

The emissivity of a material corresponds to its ability to re-emit the energy received by conduction effect (heat / cold). A low-emissive fabric limits the effect of radiation and acts as an insulator limiting losses to the outside. A low emissivity tarpaulin is generally a special fabric, woven or non-woven, most often treated with UV protection on its outer face, and covered with a layer of metal, such as aluminum, on its face. interior. Typically, a low emissivity tarpaulin is white on its outer face so as to better reflect the solar rays. According to the invention, by emissivity is meant the ratio of the energy re-emitted to the energy received.

According to the invention, the emissivity is from 0.01 to 1, preferably from 0.01 to 0.95, more preferably from 0.1 to 0.50 and even more preferably from 0.1 to 0.35.

This low emissivity is generally measured by infrared Fourier transform spectroscopy.

According to a preferred embodiment of the invention, the tarpaulin is associated, on its face intended to be brought into contact with the pile of snow, with at least one geotextile, preferably substantially over the entire said face.

The geotextile thus “doubles” the tarpaulin.

The geotextile (or felt) is, as is well known to the person skilled in the art, a large textile sheet made of synthetic material, which is permeable to fluids (water, air). A geotextile is typically a woven or a nonwoven, generally chosen from needled nonwovens and thermobonded nonwovens.

According to the invention, the geotextile is generally made of short non-woven fibers. Preferably, the geotextile is made of polyester.

The basis weight of the geotextile film is preferably between 300 and 800 g / m ² , for example equal to 500 g / m ² .

Advantageously, the presence of the geotextile makes it possible to improve the performance of snow preservation, because it traps air serving as thermal insulation. It also advantageously allows the drainage of water resulting from surface melting of snow by gravity.

Even more preferably, the geotextile itself is associated with a micro-perforated (or micro-ventilated) grid on the face opposite the tarpaulin, said micro-perforated grid being intended to be placed directly in contact with the pile of snow. In such a case, the geotextile is advantageously blocked between the tarpaulin and the grid.

The micro-perforated grid thus allows better grip of the geotextile on the snow pile, and mechanically protects the geotextile from the risks of tearing or degradation when it is in contact with snow.

The micro-perforated grid is calibrated so as to allow a good transfer of the pile of snow towards the geotextile of the humidity which is drained by the geotextile by gravity.

The micro-perforated grid is, as is well known to the person skilled in the art, a grid comprising micro-perforations distributed homogeneously. It has an openness rate typically of 10 to 25%, for example equal to 22%. It is typically made of polyester coated with PVC.

The dimensions of the geotextile and the micro-perforated grid are substantially those of the tarpaulin, however preferably with a slight shrinkage of the geotextile at the edges of the sheet, so as to allow the tarpaulin and the micro-perforated grid to be fixed directly to each other on these borders, thus enclosing the geotextile.

Particularly preferably, the tarpaulin, the geotextile and the micro-perforated grid are made integral by at least one fixing means such as a weld and / or a seam.

Such means advantageously allows the three sheets to be joined together, in at least one direction and preferably in a direction transverse to said direction. This advantageously prevents the geotextile from being distributed inhomogeneously between the two layers which enclose it, by maintaining it in its initial position which is its position when it is gripped between these layers.

By "A and / or B" is meant A, or B, or A and B.

• des moyens d'ancrage de la surface ajourée sur la bâche,
• au moins une sangle de serrage qui recouvre au moins en partie la bâche et est apte à coopérer avec lesdits moyens d'ancrage pour fixer la bâche à la surface ajourée.

According to a preferred embodiment of the invention, the system for mechanically tensioning the tarpaulin comprises:

• means for anchoring the perforated surface on the tarpaulin,
• at least one tightening strap which covers at least part of the tarpaulin and is able to cooperate with said anchoring means to fix the tarpaulin to the perforated surface.

Only the tarpaulin is mentioned here. However, this embodiment and what follows also relate to the embodiment comprising the presence of a geotextile and the possible presence of a micro-perforated grid, in the case where the tarpaulin is made integral with the geotextile and the grid. possible micro-perforated.

According to one embodiment of the invention, the perforated surface preferably comprises at least two raised sides (or ends) each comprising at least one means for anchoring the perforated surface on the tarpaulin.

According to one embodiment of the invention, said anchoring means comprise at least one fastening means fixed to the perforated surface, and said at least one strap is suitable for being linked to said fastening means. Even more preferably, said at least one strap comprises at least one tightening means making it possible to fix at least one end of said strap to said fastening means.

• au moins une pluralité de passants appartenant à au moins une des laizes et répartis parallèlement à un bord longitudinal de ladite laize, en vue de solidariser les deux laizes quand celles-ci sont sensiblement juxtaposées par leurs bords longitudinaux,
• au moins une sangle de maintien destinée à traverser les passants une fois les deux laizes juxtaposées de façon à les solidariser.

According to one embodiment of the invention, the tarpaulin comprises at least two widths intended to be assembled in pairs, each width being intended to be made integral. of at least one adjacent width by at least one assembly system. Preferably, the assembly system comprises:

• at least a plurality of loops belonging to at least one of the widths and distributed parallel to a longitudinal edge of said width, with a view to joining the two widths together when they are substantially juxtaposed by their longitudinal edges,
• at least one retaining strap intended to pass through the loops once the two widths are juxtaposed so as to secure them.

Preferably, the retaining strap corresponds to the tightening strap. This dual function of the strap (both holding and tightening) advantageously makes it possible to simplify the assembly of the structure.

According to a preferred embodiment, the structure comprises a tightening strap for all the lengths of the web.

The loops are advantageously and preferably made of fabric similar to that of the tarpaulin, and in particular of PVC, and therefore of relatively flexible material, which gives flexibility for the assembly of said structure.

According to the invention, a width (or strip) is typically, and of width from 1 m to 1.80 m, most often 1.80 m, which facilitates handling, and of length adapted to the pile of snow to be stored. , typically to cover a pile of snow having a floor area of 150 to 200 m ² . In addition, the width of the tarpaulin, whether or not doubled by the presence of a geotextile and possibly a micro-perforated grid, is preferably made of a material such that it is easily rollable or foldable, and transportable, which favors also handling and logistics operations. The widths used according to the invention of the tarpaulin, whether or not lined by the presence of a geotextile and optionally of a micro-perforated grid, are preferably substantially all of the same dimensions. The width of the tarpaulin is typically made of a textile such as a fabric canvas, for example polyester coated with polyurethane or PVC, or a plastic material, for example polyethylene. Preferably the width of the tarpaulin is a canvas comprising a PVC coating. Thus, said width is easily rollable or foldable, and transportable.

According to one embodiment of the invention, the structure further comprises a ballast system, intended to ensure the mechanical stability of the tarpaulin when the latter covers the pile of snow and improve the evenness of the pressure exerted on the snow pile. The ballast system generally includes at least one ballast.

According to one embodiment, the ballast system comprises at least two associated ballasts each making it possible to stabilize one of the ends of the tarpaulin on two opposite edges.

In the case where the tarpaulin is composed of at least two widths, a ballast is preferably placed at each end of the same width, for each width. In other words, in this case, the structure comprises two ballasts per width, each being present at one of the two ends of said width.

According to the invention, the ballast system is preferably fixed to the tarpaulin but without being placed on the ground, in order to continue to keep the tarpaulin in contact with the snow pile over time, even in the event of deformation of the pile as a result of snow settling or melting phenomena. The ballast system is preferably made of reinforced canvas, and is advantageously fixed to the tarpaulin by means of a rope system comprising one or more ropes.

According to the invention, a ballast is a pocket forming a reservoir for a heavy element intended to be fixed to a body in order to stabilize it. According to the invention, during the storage of the pile of snow, a ballast advantageously comprises a liquid such as water or a solid such as sand.

1. (a) dépôt d'une couche de neige artificielle sur une surface d'un terrain en légère pente ;
2. (b) dépôt de la surface ajourée sur ladite couche ;
3. (c) dépôt d'une autre couche de neige artificielle sur la surface ajourée;
4. (d) damage éventuel de ladite autre couche de neige artificielle ;
5. (e) répétition des étapes (c) et optionnellement (d) autant que nécessaire jusqu'à l'obtention d'un tas de neige ;
6. (f) dépôt de la bâche, doublée ou non par la présence d'un géotextile et éventuellement d'une grille micro-perforée, sur ledit tas de neige ; et
7. (g) mise sous tension mécanique de la bâche au moyen du système de mise sous tension mécanique de la bâche.

According to a second aspect, the invention relates to a method for mounting a snow storage structure according to the invention, comprising the following successive steps:

1. (a) depositing a layer of artificial snow on a slightly sloping surface of land;
2. (b) depositing the perforated surface on said layer;
3. (c) depositing another layer of artificial snow on the perforated surface;
4. (d) possible tamping of said other layer of artificial snow;
5. (e) repeating steps (c) and optionally (d) as much as necessary until a pile of snow is obtained;
6. (f) depositing the tarpaulin, lined or not by the presence of a geotextile and possibly a micro-perforated grid, on said pile of snow; and
7. (g) mechanical tensioning of the tarpaulin by means of the mechanical tensioning system of the tarpaulin.

A snow pile is an accumulation of snow, arranged in order, for storage.

Ordinary ice has a density of about 900 kg / m ³ , but snow is relatively low in density because it contains large amounts of air.The density of natural snow is most often in the range of 20 to 300 kg / m ³ , typically 40 to 180 kg / m ³ , Artificial snow (or artificial snow) has a density of approximately 330 to 450 kg / m ³ . It is more or less compacted, for example by tamping, for storage. According to the invention, the density of the snow pile is generally within a range of 700 to 800 kg / m ³ .

• les enneigeurs à canon ventilateur qui produisent eux-mêmes leur air comprimé, et génèrent de la neige par flux d'air froid par ventilateur.
• les enneigeurs « perches » qui utilisent un compresseur centralisé pour l'air comprimé. Un compresseur unique distribue l'eau sous basse pression qui passe par une turbine qui brise le jet en fines gouttelettes. La tête de ces enneigeurs doit être placée à une certaine hauteur (de 2,5 à 10 mètres, typiquement à 10 mètres de hauteur), d'où leur nom de « perches ».

A snow cannon or snow gun is a device for making snow mechanically. The principle is to project a mixture of compressed air and water in sufficiently cold weather (soil temperature typically below 4 ° C, preferably below 0 ° C). Average production is estimated at around 80 m ³ / hour, with a dispersion of around 10 to 15%. There are mainly two types of snow guns:

• fan cannon snow guns which produce their own compressed air, and generate snow by a flow of cold air using a fan.
• “pole” snow guns which use a centralized compressor for compressed air. A single compressor distributes the water under low pressure which passes through a turbine which breaks the jet into fine droplets. The heads of these snow guns must be placed at a certain height (2.5 to 10 meters, typically 10 meters high), hence their name "poles".

The "pole" snow gun is particularly well suited for the implementation of steps (a) and (c) of depositing an artificial snow layer according to the invention, because it makes it possible to optimize the stored volume thanks to the height of the perch.

The gently sloping ground allows for the drainage of melted water which may eventually, and in small quantities, flow from the pile of snow during storage. Thus, this water flows outside the snow pile, which prevents the formation of locations that weaken the storage of snow. The term “slight slope” is understood to mean according to the invention a slope of from 1 to 10%, preferably from 2 to 4%.

The layer of snow deposited during step (a), which is typically 10 cm thick, advantageously makes it possible to stabilize the structure because the perforated surface is placed on this layer, allowing sufficient anchoring to prevent the structure from slipping. on the ground over time. Indeed, the snow fills the openings of the perforated surface, and during a freezing phase is partially transformed into ice secured to said perforated surface In In addition, the structure is advantageously resistant and sufficiently rigid to withstand the repeated passage of tamping machines. It can possibly be reused over several seasons.

According to the invention, the ground surface covered by the structure corresponds to a circle of approximately 10 meters in radius. This makes it possible to envisage an average floor area of around 160m ² . The height of the snow pile is linked to the height of the snow gun, typically "pole", and can therefore reach 10 meters. Snow can also be produced by a "fan" snow gun and dispersed by means of at least one suitable device.

According to one embodiment, the perforated surface comprising at least two panels each comprising at least one means for anchoring the perforated surface on the tarpaulin, step (g) comprises, prior to the mechanical tensioning of the tarpaulin at the by means of the system for mechanically tensioning the tarpaulin, the partial covering, by at least said at least two sides of the perforated surface, of the ends of the tarpaulin on at least two opposite edges, then fixing by said anchoring means said at least two panels on said ends of the tarpaulin, so as to attach the tarpaulin to the perforated surface.

In the event that the tarpaulin, whether or not lined by the presence of a geotextile and possibly a micro-perforated grid, is formed from at least two widths intended to be assembled in pairs, each width being intended to be made secured to at least one adjacent width by at least one assembly system, two modes of implementation are possible. According to a first embodiment, the method further comprises at least one step, before step (f), of assembling the cover by said assembly system. This step is independent of steps (a) to (e) but must be carried out before step (f). However, it may be preferred for handling reasons, to proceed with a second mode in which this step of assembling the cover is carried out during step (f).

According to a preferred embodiment, the mounting method comprises an additional step, before step (f) or during step (f), of fixing, for example by gluing, at least one strip of anti- slip (“seal skin” or “climbing skin” type), on a part of the tarpaulin which will be intended to come into contact with the pile of snow, in the event that the tarpaulin is not lined by the presence of 'a geotextile and possibly a micro-perforated grid. This advantageously makes it possible to facilitate the handling during storage. Typically said strip is made of nylon and has a width of 110 to 150 mm.

Whatever the implementation, in the case where the assembly means comprises at least a plurality of loops belonging to at least one of the widths and distributed parallel to a longitudinal edge of said width, the assembly step comprises the juxtaposition of the two widths substantially by their longitudinal edges, and the insertion of at least one retaining strap through said loops in order to secure the two widths.

According to one embodiment, in the case where the structure comprises a strap tensioning system, step (g) of tensioning the tarpaulin is carried out by tensioning said at least one strap. maintenance.

This double step (both holding and tightening) advantageously makes it possible to optimize the process for mounting the structure.

According to one embodiment, in the case where the structure comprises a ballast system comprising at least two ballasts, each ballast being intended to stabilize one of the ends of the tarpaulin on two opposite edges, the method comprises an additional step, subsequent to the 'step (g), of fixing said ballasts to the tarpaulin.

Brief description of the figures

• La Figure 1 est une vue en perspective d'un premier mode de réalisation d'une structure de stockage de neige selon l'invention, représentée après qu'elle a été montée, et stockant un tas de neige.
• La Figure 2 est une coupe schématique transversale d'une partie de la structure de la figure 1.
• La Figure 3 est une vue en perspective d'un second mode de réalisation d'une structure de stockage de neige selon l'invention, représentée après qu'elle a été montée, et stockant un tas de neige.
• La Figure 4 est un agrandissement d'une partie de la structure de la figure 3.
• La Figure 5 est un agrandissement d'une autre partie de la structure de la figure 3.
• La Figure 6 est une vue schématique en perspective d'un troisième mode de réalisation d'une structure de stockage de neige selon l'invention, simplifiée par rapport aux illustrations des Figures 1 à 5.
• La Figure 7 est une schématique du système de solidarisation de la structure de la Figure 6.
• La Figure 8 est une coupe de la Figure 7.

The manner of carrying out the invention, as well as the advantages which result therefrom, emerge from the description of the embodiments which follow, in support of the appended figures in which:

• The Figure 1 is a perspective view of a first embodiment of a snow storage structure according to the invention, shown after it has been mounted, and storing a pile of snow.
• The Figure 2 is a schematic cross section of part of the structure of the figure 1 .
• The Figure 3 is a perspective view of a second embodiment of a snow storage structure according to the invention, shown after it has been mounted, and storing a pile of snow.
• The Figure 4 is an enlargement of part of the structure of the figure 3 .
• The Figure 5 is an enlargement of another part of the structure of the figure 3 .
• The Figure 6 is a schematic perspective view of a third embodiment of a snow storage structure according to the invention, simplified with respect to the illustrations of Figures 1 to 5 .
• The Figure 7 is a diagram of the system for securing the structure of the Figure 6 .
• The Figure 8 is a cut of the Figure 7 .

Of course, the dimensions and proportions of the elements illustrated in Figures 1 , 3 and 7 may have been exaggerated with respect to reality, and have been given only for the purpose of facilitating understanding of the invention.

detailed description

The snow storage structure 1 according to the invention, shown in figure 1 , comprises an openwork surface 3 placed on a slightly sloping ground 100 , a low-emissivity tarpaulin 2 , and a system 4 for mechanically tensioning the tarpaulin 2 . The tarpaulin 2 is typically made up of widths 90 cm wide and for example 15 m long for a 300 m ³ snow pile. On the figure 1 , the structure 1 was mounted by an assembly method according to the invention, as will be explained below, and stores a pile of snow (not shown) occupying on the ground, on said terrain, a substantially rectangular surface .

The cover 2 comprises two widths 21 and 22 assembled in pairs, and made integral by an assembly system 7, illustrated in more detail on the section of the figure 2 . The widths 21 and 22 extend over their length above the pile of snow so that their longitudinal edges are substantially parallel to the short sides of the rectangular surface occupied on the ground. The assembly system 7 comprises a plurality of eyelets 21c belonging to the width 21 , a plurality of loops 22d attached to the width 22 by a part 22e , and a retaining strap 4a. The eyelets 21c are openings in the cover 2 , distributed parallel to a longitudinal edge of the width 21 , regularly spaced from one another and at a distance of approximately 10 cm from said longitudinal edge. The loops 22d are advantageously formed from the same textile as the tarpaulin to avoid any thermal bridge which would have the consequence of creating water pockets forming “magnifying glasses”. They are therefore made of flexible material but represented rigid on the figure 2 to facilitate understanding. The loops 22d are distributed parallel to a longitudinal edge of the width 22 and regularly spaced from each other and at a distance of about 10 cm from said longitudinal edge. On the figure 1 , each of the loops 22d of the width 22 has been inserted into an eyelet 21c of the width 21 , and the retaining strap 4a passes through all the loops 22d and comprises a tightening means 4b , which is a loop and which cooperates with means anchoring ( 3d, 3f ) of the perforated surface 3 .

The system 4 for mechanically tensioning the tarpaulin 20 comprises the anchoring means ( 3d, 3f ) of the perforated surface 3 on the tarpaulin 2 , and a tightening strap cooperating with said means. In the case presented on the figure 1 , the retaining strap 4a corresponds to the tightening strap. Thus the strap 4a has the dual function of maintaining the two widths 21 and 22 secured to each other, and of maintaining the tarpaulin 2 in contact with the pile of snow.

The perforated surface 3 comprises two sections 3a and 3b on each side of the longitudinal edges, and two transverse sections (of which only one section, 3c , is visible) on the transverse edges, able to be raised on the snow pile, as closely as possible the snow pile, so as to close the structure 1 . Each of these panels 3a , 3b and 3c comprises at least one means for anchoring the perforated surface 3 on the tarpaulin 2 . On the figure 1 is shown this anchoring means ( 3d, 3f ) of the panel 3a , which comprises an attachment means, which is here a loop 3f , said loop 3f being attached to the panel 3a of the perforated surface 3 by a part 3d fixed on the perforated surface 3 by welding. The anchoring means ( 3d, 3f ) are all similar.

The width 21 further comprises, on its lateral edge opposite the lateral edge in contact with the width 22 , a plurality of loops 21d regularly spaced and fixed on the width 21 by means of a reinforcement 21e , through which a strap 4 'passes. , similar to strap 4, attached to panel 3a by parts 3f and 3d.

The side ends of the snow pile must of course be covered, for storage, for example by two parts 9 (only one of which is shown). Any other means can also be envisaged by the person skilled in the art, such as an insulating part, preferably fixed to the structure 1 and to cover the pile of snow as close as possible to the snow, in the same way as the cover 2 .

A part 9 , formed of 5 parts 9a, 9b, 9c, 9d and 9e welded to each other, thus covers a small side of the structure 1 . Part 9 is anchored to the side panel 3c of the surface perforated 3 by a system of two straps 9i and 9j , attached respectively to parts 9b and 9c by the respective reinforcement pieces 9g and 9h , and anchored via the tightening means which are the two respective loops 9k and 9f on the panel 3c (via parts 3f and 3d ). The part 9 is stabilized by the strap 4 ' at the width 21 . The strap 4 ' also allows part 9 to be put under tension.

It is also possible, within the framework of the invention, to use another anchoring means (not shown), for example such that the strap 4a is inserted directly into the openings of the perforated surface 3 to achieve the anchoring. of the mechanical tension system, the anchoring means in this case being made up of the relevant openings of the perforated surface 3 .

• (a) une couche de neige artificielle a été déposée au moyen d'un enneigeur « perche » sur une surface sensiblement rectangulaire du terrain 100 ;
• (b) la surface ajourée 3 a été posée sur ladite couche, la neige de la couche déposée à l'étape
• (a) entrant dans les ouvertures de ladite surface ajourée 3 ;
• (c) une autre couche de neige artificielle a été déposée sur la surface ajourée 3 ;
• (d) la couche déposée à l'étape (c) a été soumise à un damage au moyen d'une dameuse;
• (e) les étapes (c) et (d) ont été répétées autant que nécessaire jusqu'à l'obtention du tas de neige, typiquement d'un volume de 100 à 300 m³ ;
  Entre les étapes (e) et (f), la structure 9 a été déposée sur les bords latéraux et fixé sur le pan 3c par le système de sangles 9k et 9j et les boucles de serrage respectives 9k et 9f ;
• (f) les laizes 21 et 22 ont été déposées et juxtaposées sur le tas de neige sensiblement selon leurs bords longitudinaux, puis assemblées par le moyen d'assemblage 7, les passants 22d de la laize 22 étant insérés dans les œillets 21c de la laize 21, et la sangle 4a étant passée au travers desdits passants 22d pour solidariser les laizes ; et
• (g) le pan 3a a recouvert partiellement les extrémités 21a et 21b des laizes 21 et 22, l'extrémité de la sangle 4a a été fixée à la courroie 3f ce qui a permis à la fois de fixer les pans 3a et 3b, puis la bâche 2 été mise sous tension mécanique par serrage de la sangle 4a au moyen de la boucle de serrage 4b. La même opération a été réalisée sur le pan 3b (non représenté). La sangle 4' d'extrémité a également été serrée pour mettre sous tension et stabiliser la pièce 9.

Structure 1 was assembled using the following assembly method:

• (a) a layer of artificial snow has been deposited by means of a “pole” snow gun on a substantially rectangular surface of the land 100 ;
• (b) the perforated surface 3 has been placed on said layer, the snow of the layer deposited in step
• (a) entering the openings of said perforated surface 3 ;
• (c) another layer of artificial snow has been deposited on the perforated surface 3 ;
• (d) the layer deposited in step (c) has been subjected to tamping by means of a groomer;
• (e) steps (c) and (d) were repeated as much as necessary until the snow pile was obtained, typically with a volume of 100 to 300 m ³ ;
  Between steps (e) and (f), the structure 9 was deposited on the side edges and fixed on the panel 3c by the system of straps 9k and 9j and the respective tightening loops 9k and 9f ;
• (f) the widths 21 and 22 were placed and juxtaposed on the snow pile substantially along their longitudinal edges, then assembled by the assembly means 7, the loops 22d of the width 22 being inserted into the eyelets 21c of the width 21 , and the strap 4a being passed through said loops 22d to secure the widths; and
• (g) the panel 3a partially covered the ends 21a and 21b of the widths 21 and 22 , the end of the strap 4a was attached to the strap 3f which made it possible both to fix the panels 3a and 3b , then the tarpaulin 2 was put under mechanical tension by tightening the strap 4a by means of the tightening loop 4b . The same operation was carried out on panel 3b (not shown). The 4 ' end strap was also tightened to tension and stabilize part 9 .

The snow storage structure 10 according to the invention, shown in the figures 3, 4 and 5 , comprises an openwork surface 30 placed on a slightly sloping ground 200 , a tarpaulin 20 with low emissivity, and a system 40 for mechanically tensioning the tarpaulin 20 The tarpaulin 2 is typically made up of widths of 90 cm and for example 15 m long for a 300 m ³ snow pile. On the figure 3 , the structure 10 was mounted by an assembly method according to the invention, as will be explained below, and stores a pile of snow (not shown) occupying on the ground, on said terrain, a substantially rectangular surface.

The cover 20 comprises two widths 23 and 24 assembled in pairs, and made integral by an assembly system 8 , visible in more detail on the enlargement of the figure 5 . The assembly system 8 comprises a plurality of loops 23d attached to the width 23 by a part 23e , a plurality of loops 24d attached to the width 24 by a part 24e , and a retaining strap 4a. The loops 23d and 24d are advantageously formed from the same fabric as the tarpaulin to avoid any thermal bridge which would have the consequence of creating water pockets forming “magnifying glasses”. The loops 23d are distributed parallel to a longitudinal edge of the width 23 and regularly spaced from one another and at a distance of approximately 10 cm from said longitudinal edge.

On the figure 3 , the retaining strap 40a comprises a tightening means 40b , which is a ratchet tensioner (shown just before its actuation to tighten the retaining strap 40a) and which cooperates with anchoring means (30d, 30f) of the surface perforated 30. Thus the belt 30f , fixed to the side 30a of the perforated surface 30 , by the part 30d , is also secured to the retaining strap 40a .

The system 40 for mechanically tensioning the tarpaulin 20 comprises the anchoring means (30d, 30f) of the perforated surface 30 on the tarpaulin 20 , and a tightening strap cooperating with said means. In the case presented on the figure 3 , the retaining strap 40a corresponds to the tightening strap. Thus the strap 40a has the dual function of keeping the two widths 23 and 24 secured to each other, and of maintaining the cover 20 in contact with the pile of snow. Its action is represented on the figure 5 , on which we see the retaining strap 40a stretched and crossing alternately a loop 23d of width 23 and a loop 24d of width 24 .

The perforated surface 30 comprises two sections on each side of the longitudinal edges. Each of these two sections has the same means for anchoring the perforated surface 30 on the tarpaulin. 20 . On the figure 3 is shown the anchoring means ( 30d, 30f ) of the panel 3a , which comprises an attachment means, which is here a loop 30f , said loop 30f being attached to the panel 30a of the perforated surface 30 by a part 30d fixed on the perforated surface 30 by welding.

On the two small sides of the structure there is a ballast-type part 6 ensuring the closure. Only one is shown.

The structure 10 further comprises a ballast system formed of two ballasts 51 and 52 . resting respectively on the ends 23a and 24a of widths 23 and 24 .

Ballast 51 , shown in more detail on figure 4 , is an elongated pocket forming a water reservoir and stretching in the transverse direction of the width 23 , and of the same length as the width of the width 23 . It is made from the same fabric as the 23 width. It rests on the panel 30a of the perforated surface 30 which itself has been folded over the end 23a of the width 23 . It has a water inlet plug 51b and a water outlet plug 51c .

The ballast 51 is attached to the width 23 by a rope system ( 57, 59 ). The width 23 comprises a bib 23h comprising eyelets 23f to which a rope 59 is attached. The ballast 51 itself comprises eyelets 51a , through which is passed, by lacing, a rope 57 . The rope 57 hooks the ballast 51 onto the rope 59 .

No metal part is used in contact with the cover 20 . This makes it possible to avoid any thermal bridge which would have the consequence of creating locations forming “magnifying glasses”.

Ballast 52 is similar to ballast 51 . It is an elongated pocket forming a water reservoir and stretching in the transverse direction of the width 24 , and of the same length as the width of the width 24 . It is made from the same fabric as the 24 width. It rests on the panel 30a of the perforated surface 30 which itself has been folded over the end 24a of the width 24 . It has a water inlet plug 52b and a water outlet plug (not shown).

The ballast 52 is hooked to the width 24 in the same way that the ballast 51 is hooked to the width 23 , by a rope system ( 58, 60 ). The 24 width has a 24-hour bib comprising 24f eyelets to which a 60 cord is attached. The ballast 52 itself comprises eyelets 52a , through which is passed, by lacing, a rope 58 . The rope 58 hooks the ballast 52 onto the 24h bib.

There is the same ballast system (not shown) on the other ends (not shown) of the two widths 23 and 24 .

The ballast system formed by 4 ballasts stabilizes the tarpaulin 20 . The ballasts, suspended by the rope system, do not touch the ground. Thus, they can advantageously adapt over the course of storage to changes in shape that the pile of snow could take: if the pile of snow loses volume, they will descend slightly, thus allowing the cover 20 to remain in contact with the pile. of snow.

• (a) une couche de neige artificielle a été déposée au moyen d'un enneigeur « perche » sur une surface sensiblement rectangulaire du terrain 200 ;
• (b) la surface ajourée 30 a été posé sur ladite couche, la neige de la couche déposée à l'étape
• (a) entrant dans les ouvertures de ladite surface ajourée 30 ;
• (c) une autre couche de neige artificielle a été déposée sur la surface ajourée 30;
• (d) la couche déposée à l'étape (c) a été soumise à un damage au moyen d'une dameuse;
• (e) les étapes (c) et (d) ont été répétées autant que nécessaire jusqu'à l'obtention du tas de neige, typiquement d'un volume de 100 à 300 m³;
• (f) les laizes 23 et 24 ont été déposées et juxtaposées sur le tas de neige sensiblement selon leurs bords longitudinaux, puis assemblées par le moyen d'assemblage 8, la sangle 40a étant passée au travers des passants 23d de la laize 23 et au travers des passants 24d de la laize 24 pour solidariser les laizes ; et
• (g) le pan 30a a recouvert partiellement les extrémités 23a et 24a des laizes 23 et 24, l'extrémité de la sangle 40a a été fixée à la courroie 30f ce qui a permis à la fois de fixer le pan 30a, puis la bâche 20 été mise sous tension mécanique par serrage de la sangle 40a au moyen de la boucle de serrage 40b. et
• (h) le ballast 51 est accroché à la laize 23 par le système de cordage (57, 59), le cordage 57 étant lacé à travers chacun des œillets 23f, créant à chaque fois un passant que traverse la corde 59. De même, le ballast 52 est accroché à la laize 24, par le système de cordage (58, 60).

The structure 10 was assembled according to the following assembly method:

• (a) a layer of artificial snow has been deposited by means of a “pole” snow gun on a substantially rectangular surface of the land 200 ;
• (b) the perforated surface 30 has been laid on said layer, the snow of the layer deposited in step
• (a) entering the openings of said perforated surface 30 ;
• (c) another layer of artificial snow has been deposited on the perforated surface 30;
• (d) the layer deposited in step (c) has been subjected to tamping by means of a groomer;
• (e) steps (c) and (d) were repeated as much as necessary until the snow pile was obtained, typically with a volume of 100 to 300 m ³ ;
• (f) the widths 23 and 24 were placed and juxtaposed on the pile of snow substantially along their longitudinal edges, then assembled by the assembly means 8 , the strap 40a being passed through the loops 23d of the width 23 and in through loops 24d of width 24 to secure the widths; and
• (g) the panel 30a partially covered the ends 23a and 24a of the widths 23 and 24 , the end of the strap 40a was fixed to the strap 30f which made it possible both to fix the panel 30a , then the tarpaulin 20 was put under mechanical tension by tightening the strap 40a by means of the tightening loop 40b . and
• (h) the ballast 51 is hooked to the width 23 by the rope system ( 57, 59 ), the rope 57 being laced through each of the eyelets 23f , each time creating a loop through which the rope 59 passes. Likewise, the ballast 52 is hooked to the width 24 , by the rope system ( 58, 60 ).

The same steps (g) and (h) were carried out on the other side of structure 10 (not shown).

Whether it is structure 1 or structure 10 , the structure of the invention has made it possible to obtain a shelf life of the snow of a few weeks, even a few months, with a loss below 20%, in one case. where the soil temperature was below 4 ° C and the average atmospheric temperature was below 16 ° C.

The snow storage structure 70 according to the invention, shown in a simplified manner in the Figures 6 to 8 , comprises a tarpaulin 71 , a geotextile 72 and a micro-perforated grid 73 , made integral by two welds 75 and three seams 76 . The geotextile is slightly set back from the borders, which made it possible to weld the tarpaulin 71 and the micro-perforated grid 73 .

Claims (15)

Snow storage structure (1, 10, 70) comprising: - at least one perforated surface (3, 30) intended to be placed on a ground (100, 200) to maintain the structure (1, 10, 70) in a stable manner on the ground, said openwork surface (3, 30) being suitable for being covered with a pile of snow, - at least one low-emissivity tarpaulin (2, 20, 71) connected to the perforated surface, and intended to cover the pile of snow; and - at least one system (4, 40) for mechanically tensioning the tarpaulin when the latter covers the pile of snow in order to keep said tarpaulin in contact with the pile of snow. A structure (1, 10, 70) according to claim 1, in which the perforated surface is an perforated fabric, preferably a woven or a grid. Structure (1, 10, 70) according to one of claims 1 or 2, in which the system (4; 40) for mechanically tensioning the tarpaulin comprises: - anchoring means (3d, 3f; 30d, 30f) of the perforated surface (3, 30) on the tarpaulin (2, 20), - at least one tightening strap (4a, 40a) which covers at least part of the tarpaulin (2; 20) and is able to cooperate with said anchoring means to fix the tarpaulin to the perforated surface. Structure (1, 10) according to claim 3, wherein said anchoring means (3d, 3f; 30d, 30f) comprise at least one fastening means (3f, 30f) fixed to the perforated surface, and said at least a strap (4a, 40a) is adapted to be fixed to said attachment means, said at least one strap (4a, 40a) comprising at least one tightening means (4b, 40b) making it possible to fix at least one end of said strap audit means of attachment. Structure (1, 10, 70) according to one of claims 1 to 4, such that the tarpaulin (71) is associated, on its face intended to be brought into contact with the snow pile, with at least one geotextile (72 ), preferably substantially over the entire said face, the geotextile (72) itself being associated with a micro-perforated grid (73) on the face opposite the tarpaulin (71), said micro-perforated grid (73) being intended to be placed directly in contact with the snow pile. Structure (1, 10, 70) according to one of claims 1 to 5, such that the tarpaulin (2, 20) comprises at least two widths (21, 22; 23, 24) intended to be assembled in pairs, each width (21; 23) being intended to be made integral with at least one adjacent width (22; 24) by at least one assembly system (7, 8). Structure (1, 10, 70) according to claim 6, such that the assembly system (7,8) comprises: - at least a plurality of loops (22d; 23d, 24d) belonging to at least one of the widths (22; 23, 24) and distributed parallel to a longitudinal edge of said width (22; 23, 24), with a view to securing the two widths when they are substantially juxtaposed by their longitudinal edges, and - at least one retaining strap (4a, 40a) intended to pass through the loops (22d, 24d) once the widths (21, 22; 23, 24) have been juxtaposed so as to secure them. Structure (1, 10, 70) according to claim 7, in which the retaining strap (4a, 40a) corresponds to the tightening strap. Structure (10) according to one of claims 1 to 8, such that it further comprises a ballast system comprising at least two associated ballasts (51; 52) making it possible to stabilize the tarpaulin (20), each being present at a ends of the tarpaulin (20) on two opposite edges. Method for mounting a snow storage structure (1, 10, 70) according to one of claims 1 to 9, comprising the following successive steps: (a) depositing a layer of artificial snow on a slightly sloping surface of land (100, 200); (b) depositing a perforated surface (3, 30) on said layer; (c) depositing another layer of artificial snow on the perforated surface; (d) possible tamping of said other layer of artificial snow; (e) repeating steps (c) and optionally (d) as much as necessary until a pile of snow is obtained; (f) depositing the tarpaulin (2, 20, 71), whether or not lined by the presence of a geotextile (72) and possibly a micro-perforated grid (73), on said pile of snow; and (g) mechanical tensioning of the tarpaulin (2, 20, 71) by means of the system (4, 40) for mechanical tensioning of the tarpaulin (2, 20, 71). Method according to Claim 10, in which the perforated surface (3; 30) comprising at least two panels (3a, 3b; 30a) each comprising at least one anchoring means (3d, 3f; 30d, 30f) of the surface perforated (3, 30) on the tarpaulin (2, 20), step (g) comprises, prior to the mechanical tensioning of the tarpaulin (2, 20) by means of the system (4, 40) for placing mechanical tension of the tarpaulin (2, 20), the partial covering, by at least said at least two sides (3a, 3b; 30a) of the perforated surface, of the ends (21a; 23a, 24a) of the tarpaulin (2, 20) on at least two opposite edges, then the fixing by said anchoring means (3d, 3f) of said at least two panels (3a, 3b; 30a) on said ends (21a; 23a, 24a) of the tarpaulin (2 , 20), so as to attach the tarpaulin (2, 20) to the perforated surface (3, 30). Method according to one of Claims 10 or 11, in which the tarpaulin (2, 20) being formed from at least two widths (21, 22; 23, 24) intended to be assembled in pairs, each width (21; 23) being intended to be made integral with at least one adjacent width (22; 24) by at least one assembly system (7, 8), the method further comprises at least one step, before or during the step (f), assembly of the tarpaulin (2, 20) by said assembly system (7, 8). Process according to Claim 12, in which the assembly means (7,8) comprising at least a plurality of loops (22d; 23d, 24d) belonging to at least one of the widths (22; 23, 24) and distributed parallel to a longitudinal edge of said width (22; 23, 24), the assembly step comprises the juxtaposition of the two widths (21, 22; 23, 24) substantially by their longitudinal edges, and the insertion of at least one strap (4a, 40a) for maintaining through said loops (22d; 23d, 24d) in order to secure the two widths (21, 22; 23, 24). A method according to claim 13 wherein, the structure (1, 10) comprising a system for tensioning the strap (4b, 40b), the step (g) for tensioning the tarpaulin (2, 20) is carried out by tensioning said at least one retaining strap (4b, 40b). Method according to one of claims 10 to 14, wherein the structure (10) comprising a ballast system (6) comprising at least two ballasts (51, 52), each ballast (51, 52) being intended to stabilize a ends of the tarpaulin (2, 20) on two opposite edges, the method comprises an additional step, subsequent to step (g), of fixing said ballasts (51, 52) to the tarpaulin.

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